1. Field of the Invention
The present invention is directed to a drive connection joint for transmitting rotary motion from a drive shaft to a movable member.
2. Description of the Background Art
Hithertofore, universal joints provide a two-way connection between a drive shaft and a movable member. More specifically, the connection provides for limited pivotal motion between the two elements and limited sliding motion relative to the two elements. However, the normal two-way universal joint connection does not permit the necessary degrees of motion required to accommodate a three-way motion between the elements.
Centrifugal feeders are designed to utilize a rotating center disc for delivering articles from a feeder bowl onto a rim of the bowl to facilitate orientation and feeding of articles at high and low rates of feed.
A problem is encountered in the conventional arrangement of the drive mechanism for the center disc. Presently, two methods are utilized for rotating the center disc at a predetermined speed relative to the rotational speed of the feeder bowl. First, two independent drives are provided. One drive is operatively connected to the feeder bowl for imparting rotation thereto at a first predetermined speed. In addition, a second drive is operatively connected to the center disc for rotating the center disc relative to the feeder bowl at a second predetermined speed.
A second method utilizes a central drive shaft which only utilizes one drive. A complex arrangement of a stationary ramp, flexible discs and anti-friction medium of either a lubricating powder or a plastic liner disc are provided which act as a bearing medium.
Both methods described hereinabove have drawbacks. The two drive unit is complicated and expensive. The flexible disc method is also complicated and expensive and induces a factor of friction between the rubber flexible disc and the stationary ramp. The frictional factor changes over time and must be overcome during the operation of the centrifugal feeder. This can cause changes in the feeding performance over the life cycle of the centrifugal feeder.